title: Lack of transparency of clinical trials on endometriosis.
abstract: OBJECTIVE
  To estimate patterns of publication of clinical trials of endometriosis registered in ClinicalTrials.gov and their associated characteristics.
  
  
  METHODS
  Information on interventional clinical trials on endometriosis that were registered at ClinicalTrials.gov and updated as having been completed by October 25, 2012, was retrieved and the publication status and time to publication in Medline-indexed journals were ascertained by searching PubMed and by sending e-mail inquiries to the principal investigators listed by the registry.
  
  
  RESULTS
  Seventy-one interventional trials of endometriosis, testing various drugs and biologicals, were identified. Among them, 49.3% (35/71) were completed by October 25, 2012, 21.1% were either stopped or inactive in the past 2 years, and the remaining 29.6% were ongoing. Among the 35 completed trials, 25 (71.4%) were sponsored by industry and results were published for only 11 (31.4%; five industry-sponsored, and six nonindustry-sponsored). Trials sponsored by industry were nearly four times less likely to publish their results than nonindustry-sponsored trials, even though these trials typically had larger sample sizes and were completed faster. Compared with the publication rate of 20% found 4 years ago, the current rate has increased only marginally but still lies significantly below the reported 66.3% surveyed recently among 546 completed nonendometriosis trials registered at ClinicalTrials.gov (P<.001).
  
  
  CONCLUSIONS
  Despite mounting pressure on more transparency of clinical trials, the current state of transparency or lack thereof of clinical trials on endometriosis is worrisome and does not benefit the trial sponsor or the public. Thus, we again call for more transparency for endometriosis trials.
authors.affiliation: Shanghai Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China; and the Division of Reproductive Medicine and Biology, School for Oncology and Developmental Biology GROW, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Sun-Wei
authors.initials: SW
authors.lastname: Guo
authors.forename: Johannes L H
authors.initials: JLH
authors.lastname: Evers
mesh_terms: D002986:Clinical Trials as Topic / Q000941:ethics* / Q000706:statistics & numerical data; D004345:Drug Industry / Q000941:ethics* / Q000706:statistics & numerical data; D004715:Endometriosis / Q000188:drug therapy*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D017594:Publication Bias